E! Entertainment – NBCU Photo Bank via Getty Images/Heidi Gutman(LOS ANGELES) — The cast and crew of the former CW show One Tree Hill on Monday accused creator and showrunner Mark Schwahn of sexual harassment, in support of a Twitter accusation over the weekend by one of the show’s writers, Audrey Wauchope.

In a joint statement to Variety, the cast and crew, including stars Sophia Bush, Hilarie Burton, and Bethany Joy Lenz write, in part, “Mark Schwahn’s behavior over the duration of the filming of One Tree Hill was something of an ‘open secret.’ Many of us were, to varying degrees, manipulated psychologically and emotionally. More than one of us is still in treatment for post-traumatic stress. Many of us were put in uncomfortable positions and had to swiftly learn to fight back, sometimes physically, because it was made clear to us that the supervisors in the room were not the protectors they were supposed to be.”

The statement added, “More than one woman on our show had her career trajectory threatened.”

In a series of tweets Saturday, Wauchope — without naming the show or Schwahn — alleged that female writers on a past show on which she was writer would position themselves in meetings so as not to be touched by the showrunner who, she also alleged, once showed men on the set naked photos of an actress he was dating without the actress’s knowledge. Wauchope also accused the showrunner of propositioning her writing partner on the eve of her wedding.

It was the open letter from the One Tree Hill cast and crew that named the show, and Schwahn as the alleged perpetrator. A rep for Schwahn told ABC News, “Mark is speaking with his attorney and will decide soon if he is making a statement.”

E!, the network that hosts Schwahn’s current show, The Royals, also released a statement, declaring: “We are monitoring the information carefully. E!, Universal Cable Productions and Lionsgate Television are committed to providing a safe working environment in which everyone is treated respectfully and professionally.”

The CW, which aired One Tree Hill from 2006 to 2012, did not immediately return ABC News’ request for comment.